When something is a worse version of an existing person/item.
Comes from a meme about how the commonly shared experience of asking your parents for fast food and being told "there's food at home." With the food at home always being something horrible.
The neighbor and friend you grew up with that is now way too embarrassing to hang out with at school, but is sorta ok to hang out with when you are at home with nothing to do.
Yes, we were friends in grammar school but now she's pretty much an "at home only friend."
request to simplify the language, avoid fancy titles etc. uses the idea that at home, peopledon't bother trying to sound impressive. calling a spade a spade.